Conventional electrically conductive adhesive tapes comprise an electrically conductive tape support and an electrically conductive pressure-sensitive adhesive layer containing dispersed therein electrically conductive powders. These tapes, however, suffer from the disadvantage that the adhesive strength of the adhesive layer is not satisfactorily sufficient because powder, e.g., non-sticky carbon, is compounded or dispersed therein.
An electrically conductive adhesive tape in which a pressure-sensitive adhesive layer is provided on one surface of the electrically conductive tape support and the resulting laminate is embossed to form a number of fine projections or lines sharped at predetermined intervals has been proposed to overcome the above-described problem. When voltage is applied across the electrically conductive adhesive tape bonded to the electrically conductive substrate, the adhesive layer causes dielectric breakdown at the areas contacting the fine projections or lines sharped, so that an electric current can pass through the tape. In such a tape, however, the fine projections or lines sharped are again covered with the adhesive layer when external pressure is applied to the bonded tape or by fluidity of the adhesive layer and, as a result, the electric resistance of the tape seriously increases.